Formation and Characterization of ER4043 Welding Wire Layers by CA-WAAM on Copper Substrates

In this work, the possibility of forming aluminium ER4043 layers using a wire arc additive manufacturing (WAAM) setup in the cold arc (CA) mode on copper substrates was investigated. This is a challenging process due to the poor miscibility of copper and aluminium, and due to the possible formation of intermetallic compounds (IMCs), which would result in accelerated formation of defects, particularly cracks, in the zone of contact between the two materials. The effect of two different technological parameters was investigated, namely the wire feeding rate (WFR), the application of pulses to the process (+SP), and the formation of layers without pulses (–SP). Wire feeding rates of 67 mm/s and 133 mm/s were employed. The results indicated that in the case of applying a layer using a WFR of 133 mm/s without pulses a homogeneous, dense structure was formed with a preferred crystallographic orientation towards the {311} family of planes. In this case, the obtained microhardness was also the highest with an average value of 100 HV0.1. During the investigations, no IMCs were detected. The results indicate that the formed layer can be successfully implemented in the field of wire arc additive manufacturing as a foundation for the manufacturing of bimetallic components made of, in this case, copper and aluminium alloy ER4043.